Compressing apparatus for container forming machine

ABSTRACT

An improved compressing apparatus for a container-forming machine providing a frame adapted to position a planar foldable container blank in a substantially planar assembly position with a pair of separate end panels disposed in substantially rightangular relation thereto and including coacting mandrel and die means on the frame operably concurrently to thrust the blank and the end panels through a substantially rectilinear path in a direction normal to the plane of the blank so as to fold the blank about the end panels in a container-forming position with the overlapping portions thereof providing at least one glued surface therebetween. The improvement of the present invention provides blank-compressing means mounted in fixed position on said die means in tightly pressing relation to said folded, overlapping portions of the blank and said end panels during said thrusting operation of the mandrel and die means.

United States Patent 3,456,563 7/1969 Roesner et al.

ABSTRACT: An improved compressing apparatus for a container-formingmachine providing a frame adapted to position a planar foldablecontainer blank in a substantially planar assembly position with a pairof separate end panels disposed in substantially right-angular relationthereto and including coacting mandrel and die means on the frameoperably concurrently to thrust the blank and the end panels through asubstantially rectilinear path in a direction normal to the plane of theblank so as to fold the blank about the end panels in a contamer-formingposition with the overlapping portions thereof providing at least oneglued surface therebetween. The improvement of the present inventionprovides blank-compressing means mounted in fixed position on said diemeans in tightly pressing relation to said folded, overlapping portionsof the blank and said end panels during said thrusting operation of themandrel and die means.

PATENIED um 1 219?] SHEEI 3 OF 3 //6 xko GERALD C. PAXTON IN VE N 70/?04 A 7'TORNEYS COMPRESSING APPARATUS FOR CONTAINER FORMING MACHINECROSS-REFERENCE TO RELATED APPLICATIONS The present invention generallyrelates to the containerforming art and is particularly adapted for usewith the container-forming machine shown in copending application Ser.No. 757,581 filed Sept. 5, I968 entitled Method and Machine for FormingContainers.

BACKGROUND OF THE INVENTION The above designated copending applicationdiscloses a container-forming machine which has been proven ideallysuited for the intended purpose and has enjoyed substantial commercialsuccess. It was recognized, however, that certain improvements'could bemade to the structure thereof for greater simplicity and ease ofoperation particularly with respect to the container compressing andforming portion of the machine; The prior machine employed coactingmandrel and die means which were effective partially to fold thecontainer blank in overlapping relation to the end panels of thecontainer to be formed with the die means mounting a pair of oppositelaterally movable compressing plates for completing the foldingoperation and adhesively bonding the blank to the end panels. Suchmovement had to be precisely synchronized with the termination of theinitial thrusting movement of the mandrel and container forming blankinto the die means and then subsequently retracted to permit withdrawalof the mandrel from the formed container and die means. This required arelatively large number of moving parts susceptible to wear and acomplicated control system for such synchronized operation. It was,therefore, recognized that the forming operation and the structure ofthe machine could be greatly simplified if it were possible to form thecontainer with a single-thrusting movement of the mandrel into the diemeans thus eliminating the additional lateral compressing operation.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide an improved compressing apparatus for acontainerforrning machine.

Another object is to provide such an improved compressing apparatuscapable of fully forming a container by a singlethrusting movement of ablank-conveying mandrel into a die structure without requiring anyadditional lateral compressing operations.

Another object is to provide an improved compressing apparatus of thecharacter described which is adapted successively to form a relativelylarge number of containers in a rapid, reliable manner.

Another object is to provide an improved compressing apparatus in whichthe previously formed containers are automatically ejected during eachsuccessive forming operation.

Another object is to provide an improved compressing apparatus whichemploys a coacting mandrel and die structure which is adaptedsuccessively to receive container-forming blanks and separate end panelshaving predetermined glue carrying portions in a substantially uprightposition in order to conserve floor space with the mandrel beingeffective to force the assembled blanks and end panels into the diestructure past a plurality of preliminary blank-folding cams and plowson the die structure foldably to overlap the glued areas of the blanksand end panels with the die means providing a plurality of finalcompressing rollers disposed in freely rotating substantiallyfrictionless compressing engagement with the overlapping portions of theblank and end panels for adhesively bonding them in container-formingrelation.

Other objects and advantagesof the present invention will subsequentlybecome more-clearlyapparent upon reference to the following descriptionand accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of acompressing apparatus for a container-forming machine embodying theprinciples of the present invention.

FIG. 2 is a longitudinal vertical sectionrthrough the compressingapparatus, taken generally along the line 22 of FIG. )1.

FIG. 3 is an end elevation of the compressing apparatus of the presentinvention with portions broken away for illustrative convenience.

FIG. 4 is a somewhat enlarged, fragmentary, horizontal section throughthe mandrel and die means disposed in a container forming position.

FIG. 5 is a perspective view of the mandrel and die means with afinished container disposed therein and with the mandrel retracted fromthe die means.

FIG. 6 is a perspective of a container-forming blank prior to itsintroduction into the compressing apparatus of the present invention.

FIG. 7 is a perspective of an alternative type of container which isadapted to be produced by the compressing apparatus of the presentinvention without any modification thereto.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawings, a compressing apparatus embodying the principles oftheipresent invention is disclosed for use with a container-formingmachine of the type shown and described in copending application Ser.No. 757,581. The compressing apparatus provides a reciprocalsubstantially rectangular boxlike mandrel 10 which operationally coactswith a similarly shaped die 12 havinga mandrel-receiving compressionchamber 14 therein. With the mandrel disposed in its retracted positionof FIGS. l-and 2, there is formed a container blank assembly station 16between the mandrel and the die into which a substantially flat con.-tainer fonning blank, such as that indicated by the reference numeral 18in FIG. 6, is adapted to be disposed in a substantially uprightposition. A pair of transversely opposed end panel feed magazines 20,having a plurality of end panels 21 loaded thereon, are individuallydisposed on opposite sides of the mandrel for assembly with thecontainer-fonning blank 18 in the assembly station 16.

As best shown in FIG. 6, the container-forming blank is of predeterminedplanar configuration and has a central main body portion 25 havingopposite top andbottom side panels 26 and 27, respectively, foldablewith respect to the body portion along scored lines 29. The top andbottom side panels individually include opposite end gluing flaps 32 and34, respectively, which are foldable from the panels along scored lines36 and 37, respectively. The end gluing flaps 32 and 34 respectivelyprovide inner beveled ends 38 and 39 in angularly outwardly extendedrelation from their respective scored lines 29. The main body portion 25also has opposite end gluing flaps 42 having opposite beveled ends 43fonning with their respectively adjacent beveled ends of the end gluingflaps of the top and bottom side panels triangular-shaped notches 45 inthe opposite edges of the container-forming blank 18.

The mandrel l0 and die I2 of the present invention are mounted upon abase 50 having a plurality of crossmembers, one of which is indicated bythe reference numeral 52. A pair of elongated support rails 55 aremounted on the crossmembers 52 in substantially right angular relationthereto and in spaced substantially parallel relation to eachother. Thespacing between the support rails is determinedby an elongated spacerbar 56 secured to the cross member 52by a pluralityof screw-threadedbolts 57 extended therethrough. Oppositeend bolts 58 are extendedthroughthesupport rails and .endwardly into the spacer bar to maintainthe support rails in their desired spaced relation. It will be notedthatdifi'erent length spacer bars can be employed to vary thespacingbetween the support rails.

The die 12 is mounted on the support rails of the base 50 and generallyprovides a substantially rectangular open frame having a forwardblank-receiving end 62 and an opposite rearward open container dischargeend 63. The die frame includes forwardly and rearwardly disposedsubstantially rectangular chamber-forming supports 65 and 66,respectively, disposed in substantially upright spaced relation on thesupport rails 55. The forward and rearward supports are substantiallyidentical and individually provide a lower crossmember having oppositesegmented ends 72 bolted to their respectively adjacent top surfaces ofthe support rails. The lower crossmembers include spaced inner ends 73which are tied together by an elongated bridging strap 75 having aplurality of bolts 76 extended through elongated adjusting slots 77therein.

Adjacent to each of the opposite ends 72 of the lower crossmember ismounted a substantially upstanding corner post 80 having a lower tubularsleeve 82 secured, as by welding or the like, to the crossmember and anopposite elongated upper rod 84 telescopically axially slidable withinthe lower sleeve. An annular collar 85 is disposed on the upper end ofthe lower sleeve and has a setscrew 86 mounted therein which is adaptedto be tightened against the rod 84 of the corner post dependably to holdthe rod in selected elevationally extended positions.

An upper crossmember 90 substantially identical to the lower crossmember70 is mounted in bridging relation between the upper ends of the rod 84of the oppositely disposed comer posts 80. The upper crossmemberincludes laterally spaced end sections 92 having outer ends 93 rigidlysecured to the upper ends of the corner post rods and spaced inner ends94 longitudinally adjustably connected by an elongated bridging strap95. The bridging strap is rigidly secured in such position by aplurality of bolts 96 extended through elongated slots 97 in the strap.

The forward and rearward supports 65 and 66 are intercon nected at eachside of the die frame 60 by a pair of top and bottom side rails 100 and102, respectively, disposed inwardly adjacent to the comer posts 80 ofthe forward and rearward supports 65 and 66. Each of the rails freelyrotatably mounts a plurality of compression rollers having innerperipheries 106 disposed in a common plane laterally adjacent to thecompression chamber 14 within the die 12. It will be noted that the topand bottom rails are substantially identical except that the top railsare inverted so that the rollers 105 are supported in depending relationtherefrom.

A pair of sets of upper and lower panel camming straps 110 and 111,respectively, are mounted in forwardly extended relation from the dieframe 60 in spaced, substantially parallel relation. Each of the cammingstraps has a rearward end 114 connected to its respectively associatedupper and lower crossmember 90 and 70 in edgewardly abutting relation toits associated top and bottom rail 100 and 102. Each of the cammingstraps has a forwardly extended arcuately curved camming portion 116outwardly curved away from the compression chamber 14 with the strapterminating in a rearwardly angularly extended forward end 118 providinga forward blank-engaging edge 120. As best shown in FIG. 2, the forwardcamming portions of the upper and lower camming straps arcuatelyoutwardly diverge to funnel the containerforming blanks into thecompression chamber.

A pair of sets of upper and lower flap folding plows are mounted on theforward ends of the top and bottom rails 100 and 102, respectively, andprovide outwardly contoured camming surfaces 127 for engaging the endgluing flaps 32 and 34 of the top and bottom side panels 26 and 27 ofthe container blank 18. A pair of elongated substantially vertical compression bars 130 having opposite upper and lower ends 132 and 133,respectively, are slidably extended through notches 135 and 136 in therearward ends of the top and bottom side rails 100 and 102. A lockingbolt 138 is extended through the rearward end of the top side rails 100and into their associated compression bars for dependably constrainingthe bars in their described positions. The lower ends of the compressionbars are slidable through their respective notches in the bottom siderails during vertical adjustment of the forward and rearward supports 65and 66 of the die frame 60. The compression bars individually include aninner compression surface 140 and a forwardly disposed beveled edge 142for guiding the end gluing flaps of the container blank onto the innersurface.

A pair of laterally oppositely disposed substantially upright supportposts are supported in upstanding relation from the inner surface of thesupport rails 55 of the base 50 on opposite sides of the container blankassembly station 16 between the mandrel 10 and the die 12. Each of theposts has a forward surface 152 connected in supporting relation, as bywelding or the like, to its respectively associated end panel magazine20 and an opposite rearward surface 153. Each of the posts includes aninner surface 155 which mounts an elongated blank-guiding strip 157having a lower end 158 terminating in a plane disposed well below thetop side rails 100 of the die frame 60.

A pair of elongated container-stripping plates 160 are individuallydisposed along the opposite sides of the die frame 60 substantiallyintermediate the top and bottom side rails 100 and 102. Each of thestripping plates has a forwardly disposed shoe mounting end 162 havingopposite angularly extended container camming ends 164 with the shoebeing mounted on the rear surface 153 of its respectively associatedsupport post 150. Each of the stripping plates includes an oppositedistal end 166 which is angularly inwardly bent for extension into thecompression chamber 14 within the die frame 60. The distal end includesa substantially straight edge 168 which is engageable with the endgluing flap 42 of the main body portion 25 of the container blank 18.

The mandrel 10 of the present invention is reciprocably mounted on thebase 50 for movement from its retracted position of FIGS. 2 and 5 to acompressing position disposed within the compression chamber 14 of thedie frame 60 as shown in FIG. 3. The mandrel provides a substantiallyrectangular frame which, as best shown in FIG. 3, is of a somewhatsmaller size than the compression chamber 14 and has a plurality ofangle iron corner beams 170 transversely interconnected by a pluralityof tubular cross rods 172. A plurality of inwardly disposed plates 173are individually mounted on the comer beams to support thcrebetweenvertically disposed sideplates 175. A centrally disposed cross rod 176is extended between the sideplates and pivotally mounts an elongatedpush arm 178 connected at its opposite end to a reciprocating powersource, not shown, on the container-forming machine. A pair of upper andlower end panel feed bars 180 have forward edges 182 for engaging therearward edge of the forwardmost end panel 21 on the magazines 20. Thefeed bars are adjustably mounted on their respective comer beams 170 bya plurality of bolts 183 extended through elongated slots 185 therein inorder to adjust for different sizes of end panels.

An alternate form of container, generally indicated by the referencenumeral in FIG. 7, may also be formed in the compressing apparatus ofthe present invention without any modification thereto. Such containeris of the type employed as a fruit packing tray having relativelyshallow top and bottom sidewalls 192 and 193, respectively, and oppositesidewalls 194. The top and bottom walls include end gluing flaps 196which are folded around the comers of the container in overlappingbonded relation to the opposite sidewalls.

OPERATION The operation of the described embodiment of the subjectinvention is believed to be clearly apparent and is briefly summarizedat this point. The carton-forming blank 18 is extended downwardlythrough a substantially rectilinear path of travel into the assemblystation 16 between the mandrel 10 and the die 12 by a blank propellingand flap gluing section of the machine, not shown, which is fullydescribed and shown in the above designated copending application. Thecontainer blank is guided downwardly between the support posts 150against the guide strips 157 thereon until the blank is substantiallycentered in the position shown in FIG. 2 with the upper and lower edgesthereof extended somewhat beyond their respectively adjacent forwardedges 120 of the upper and lower camming straps 110 and 111. During suchdownward movement of the blank to the position of FIG. 2, cocking of theblank into the compression chamber 14 within the die frame 60 isprecluded by the upper angular end of the shoes 162 of the strippingplates 160.

Upon full deposit of the container-forming blank 18 into the assemblystation 16, the push arm 178 is effective to propel the mandrel in asubstantially horizontal direction of movement from left to right, asviewed in FIGS. 2 and 5, for engagement with the container-formingblank. During such initial movement of the mandrel, the end panel feedbars 180 engage the rearward edge of the forwardmost end panel 21 on themagazines 20 to position the end panels in edgeward engagement with thecontainer-forming blank 18. Upon continued movement of the mandrel, thetop and bottom side panels 26 and 27 of the container-forming blankengage the arcuate forward end portions 116 of the camming strapspreliminarily to fold them inwardly toward the upper and lower ends ofthe end panels 21. At the same time, the end gluing flaps 42 of the mainbody portion 25 of the blank are folded inwardly toward the end panelsby engagement with the stripping plates 160.

As the mandrel l0 continues inwardly into the compression chamber 14within the die frame 60, the end gluing flaps 32 and 34 of the top andbottom side panels 26 and 27, respectively, engage their respectivelyassociated folding plows 125 for preliminary folding of them toward theend panels 21. Upon further movement of the mandrel, the end gluingflaps 32 and 34 engage the inner peripheries 106 of the compressionrollers 105 on the top and bottom side rails 100 and 102 with therollers providing substantially frictionless compression of the endgluing flaps in tightly bonding relation to the end panels 21 againstthe sideplates 175 of the mandrel. Accordingly, each of the end flaps iscontinually compressed upon successive engagement with the series ofrollers for insuring a dependable bond between the flaps and the endpanels.

As the mandrel l0 approaches the discharge end 63 of the die frame 60,the end gluing flaps 42 on the main body portion 25 of the containerblank are folded inwardly against the end panel 21 by the angular distalends 166 of the stripping plates 160. Such end flaps then engage thebeveled forward edges [42 of the compression bars 130 which guide theflaps between the compression bars and the adjacent end panels 2]. lnsuch position, the distal ends 166 of the stripping plates are permittedto spring inwardly against the end panels in a position edgewardly toengage the end flaps 42. The mandrel 10 is retracted from thecompression chamber 14 with the stripping plates 160 being effective tohold the formed container within the discharge end of the die frame 60.The newly formed container remains in such position until the nextcontainer-forming blank 18 is thrust into the compression chamber by themandrel which engages and automatically ejects the preceding containerfrom the rearward discharge end 63 of the die frame.

The alternate tray-type container 190 of FIG. 7 is formed insubstantially the same manner as that described during the formation ofthe container from the blank 18 of P16. 6. ln such operation, the topand bottom walls 192 and 193 are folded upon engagement with the upperand lower camming straps 110 and 111, respectively; the sidewalls 194are folded by the stripping plates 160 and subsequently compressed bythe compression bars 130; and the end flaps 196 are initially folded bythe plows 125 and compressed in tightly bonding relation against thesidewalls 194 by the compression rollers 105.

In view of the foregoing, it is readily apparent that the structure ofthe present invention provides an improved compressing apparatus for acontainer-forming machine which is effective fully to form a containertherein with a single thrust of the mandrel into the compression chamberof the die frame without any separate lateral compressing operations.The im' proved compressing apparatus is adapted successively to form arelatively large number of containers in a wide varietyof sizes and in arapid and reliable manner with the newly formed containers therein beingautomatically ejected upon the formation of succeeding containers.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures maybe made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

Having described my invention, what I claim as new'and desire to secureby Letters Patent is:

1. In a container-forming apparatus including a coacting mandrel and diemeans having a compressing compartment and in which the mandrel isreciprocated to and from the compartment to thrust foldable containerblank means into the compartment in a predetermined direction wherebythe die means folds a portion of the blank means constituting a gluingflap back over another portion of the blank means to which the flap isto be secured and to retract from the die means; an elongatedcontainer-stripping plate having a mounting end secured in fixedrelation to the die means and a flexible distal end extended from themounting end in the direction of movement of the mandrel into thecompartment to engage the gluing flap to fold it against said anotherportion, said distal end having a container-stripping edge movableinwardly against said another portion of the blank means upon movementof said gluing flap therepast and being edgewardly engageable with saidgluing flap to preclude return movement of the formed container uponretraction of the mandrel from the compartment.

2. ln an apparatus for forming a container providing a frame adapted toposition a planar foldable container blank in a substantially planarassembly position with a pair of separate end panels disposed insubstantially right-angular relation thereto and including coactingmandrel and die means on the frame operable concurrently to thrust theblank and the end'panels through a substantially rectilinear path in adirection normal to the plane of the blank so as to fold the blank aboutthe end panels in a container-forming position with the overlappingportions thereof providing at least one glued surface therebetween; theimprovement comprising blank-compressing means mounted in fixed positionon said die means in tightly pressing relation to said foldedoverlapping portions of the blank and said end panels during saidthrusting operation of the mandrel and die means, said container blankhaving a main body portion and opposite top and bottom side panelsfoldable therefrom and said body portion and side panels having foldableend gluing flaps disposable in overlapping relation to said end panelswith said compressing'means on said die means foldably pressablyengaging said end gluing flaps on said side panels against the endpanels; combination flap folding, compressing, and retaining means onsaid die means concurrently foldably engaging said end gluing flaps ofsaid main body portion toward and against said end panels andrestraining return movement of the container formed within said diemeans along said path during subsequent separation of said mandrel anddie means, said die means including a substantially rectangular framehaving opposite sets of top and bottom side rails laterallyinterconnected in circumscribing relation to a blank compressing chambertherein, said mandrel providing a substantially rectangularblank-thrusting frame having spaced substantially parallelsides-reciprocal between said container forming position disposed withinsaid'blankcompressing chamber of the die means and said blank assemblyposition retracted from the compressing chamber with saidmandrel-including means on said sides thereof for feeding said endpanels into said compressing-chamber with the container blank, saidcompressing means being mounted in fixed position on said top and bottomside rails of the die means in closely spaced relation to said sides ofthe mandrel when the latter is disposed within said compressing chamberin tightly compressing relation to said end gluing flaps of the top andbottom side panels of the container blank and the portions of the endpanels overlapped thereby, said compressing means including a pluralityof sets of rollers individually freely rotatably mounted along said topand bottom side rails of the die means with the rollers of each sethaving inner peripheries disposed substantially tangentially to a commonplane mar ginally along said compressing chamber in substantiallyfrictionless rolling compressing relation to said end gluing flaps ofthe top and bottom side panels; a plurality of contoured flap plowsindividually mounted on said top and bottom side rails of the die meanswithin said path of the container blank into said compressingcompartment ahead of their respectively adjacent sets of compressingrollers initially to engage and to fold said end gluing flaps of the topand bottom side panels inwardly toward their associated end panels; andan elongated substantially flat container-stripping plate having amounting end secured to said die means in longitudinally extendedrelation substantially intermediate each of said top and bottom siderails and an opposite flexible distal end angularly inwardly extendedinto said compressing compartment past said plane of the rollers forfolding its respectively associated end gluing flap of the main bodyportion of the container blank inwardly toward its respectivelyassociated end panel, said distal end having a container-stripping edgemovable inwardly against said end panel upon movement of said end gluingflap therepast and being edgewardly engageable with said end gluing flapof the main body portion of the container blank to preclude returnmovement of the formed container along said path during retraction ofsaid mandrel from said compressing compartment of the die means.

3. The improvement of claim 2 wherein said formed container isautomatically ejected from the die means by movement in the samedirection as when formed by the introduction of a succeeding containerblank into said compressing compartment.

4. The improvement of claim 2 in which said combination flap folding,compressing, and retaining means further includes an elongatedsubstantially upright flap compressing bar mounted on said die meansbetween each of said top and bottom side rails in closely spacedadjacent relation to its respectively adjacent side of the mandrel whenthe latter is disposed within the compressing compartment in compressingrelation to its respectively adjacent end flap of the main body portionof the container blank.

5 The improvement of claim 4 including extendibleretractable supportmeans interconnectably vertically extended between the top and bottomside rails of each set of side rails at the opposite sides of said diemeans, and extendi ble-retractable means interconnectably longitudinallyextended between the corresponding pairs of top and bottom side rails atthe opposite sides of the die means adjustably to vary the size of saidcompressing compartment for forming various sizes of containers therein.

1. In a container-forming apparatus including a coacting mandrel and diemeans having a compressing compartment and in which the mandrel isreciprocated to and from the compartment to thrust foldable containerblank means into the compartment in a predetermined direction wherebythe die means folds a portion of the blank means constituting a gluingflap back over another portion of the blank means to which the flap isto be secured and to retract from the die means; an elongatedcontainer-stripping plate having a mounting end secured in fixedrelation to the die means and a flexible distal end extended from themounting end in the direction of movement of the mandrel into thecompartment to engage the gluing flap to fold it against said anotherportion, said distal end having a container-stripping edge movableinwardly against said another portion of the blank means upon movementof said gluing flap therepast and being edgewardly engageable with saidgluing flap to preclude return movement of the formed container uponretraction of the mandrel from the compartment.
 2. In an apparatus forforming a container providing a frame adapted to position a planarfoldable container blank in a substantially planar assembly positionwith a pair of separate end panels disposed in substantiallyright-angular relation thereto and including coacting mandrel and diemeans on the frame operable concurrently to thrust the blank and the endpanels through a substantially rectilinear path in a direction normal tothe plane of the blank So as to fold the blank about the end panels in acontainer-forming position with the overlapping portions thereofproviding at least one glued surface therebetween; the improvementcomprising blank-compressing means mounted in fixed position on said diemeans in tightly pressing relation to said folded overlapping portionsof the blank and said end panels during said thrusting operation of themandrel and die means, said container blank having a main body portionand opposite top and bottom side panels foldable therefrom and said bodyportion and side panels having foldable end gluing flaps disposable inoverlapping relation to said end panels with said compressing means onsaid die means foldably pressably engaging said end gluing flaps on saidside panels against the end panels; combination flap folding,compressing, and retaining means on said die means concurrently foldablyengaging said end gluing flaps of said main body portion toward andagainst said end panels and restraining return movement of the containerformed within said die means along said path during subsequentseparation of said mandrel and die means, said die means including asubstantially rectangular frame having opposite sets of top and bottomside rails laterally interconnected in circumscribing relation to ablank compressing chamber therein, said mandrel providing asubstantially rectangular blank-thrusting frame having spacedsubstantially parallel sides reciprocal between said container formingposition disposed within said blank-compressing chamber of the die meansand said blank assembly position retracted from the compressing chamberwith said mandrel-including means on said sides thereof for feeding saidend panels into said compressing chamber with the container blank, saidcompressing means being mounted in fixed position on said top and bottomside rails of the die means in closely spaced relation to said sides ofthe mandrel when the latter is disposed within said compressing chamberin tightly compressing relation to said end gluing flaps of the top andbottom side panels of the container blank and the portions of the endpanels overlapped thereby, said compressing means including a pluralityof sets of rollers individually freely rotatably mounted along said topand bottom side rails of the die means with the rollers of each sethaving inner peripheries disposed substantially tangentially to a commonplane marginally along said compressing chamber in substantiallyfrictionless rolling compressing relation to said end gluing flaps ofthe top and bottom side panels; a plurality of contoured flap plowsindividually mounted on said top and bottom side rails of the die meanswithin said path of the container blank into said compressingcompartment ahead of their respectively adjacent sets of compressingrollers initially to engage and to fold said end gluing flaps of the topand bottom side panels inwardly toward their associated end panels; andan elongated substantially flat container-stripping plate having amounting end secured to said die means in longitudinally extendedrelation substantially intermediate each of said top and bottom siderails and an opposite flexible distal end angularly inwardly extendedinto said compressing compartment past said plane of the rollers forfolding its respectively associated end gluing flap of the main bodyportion of the container blank inwardly toward its respectivelyassociated end panel, said distal end having a container-stripping edgemovable inwardly against said end panel upon movement of said end gluingflap therepast and being edgewardly engageable with said end gluing flapof the main body portion of the container blank to preclude returnmovement of the formed container along said path during retraction ofsaid mandrel from said compressing compartment of the die means.
 3. Theimprovement of claim 2 wherein said formed container is automaticallyejected from the die means by movement in the same direction as whenformed by the introductiOn of a succeeding container blank into saidcompressing compartment.
 4. The improvement of claim 2 in which saidcombination flap folding, compressing, and retaining means furtherincludes an elongated substantially upright flap compressing bar mountedon said die means between each of said top and bottom side rails inclosely spaced adjacent relation to its respectively adjacent side ofthe mandrel when the latter is disposed within the compressingcompartment in compressing relation to its respectively adjacent endflap of the main body portion of the container blank.
 5. The improvementof claim 4 including extendible-retractable support meansinterconnectably vertically extended between the top and bottom siderails of each set of side rails at the opposite sides of said die means,and extendible-retractable means interconnectably longitudinallyextended between the corresponding pairs of top and bottom side rails atthe opposite sides of the die means adjustably to vary the size of saidcompressing compartment for forming various sizes of containers therein.